The transcription factor, signal transducer and activator of transcription 3 (STAT3), is activated inappropriately in a wide range of human cancers, and drives the malignant behavior of cancer cells. Extensive published evidence indicates that inhibition of STAT3 can have a therapeutic effect on cancer cells, while having minimal toxicity to normal tissue. Further, the mTOR pathway is known to be involved in cancer cell growth and survival (see, e.g., Laplante et al. (2012), su Laplante, M. et al. Cell. 2012 Apr. 13; 149(2): 274-293). Although evidence suggests that inhibiting STAT3 or mTOR would be an effective form of cancer therapy (by itself or in conjunction with chemotherapy, immunotherapy, targeted therapy, and/or radiation therapy), it has been extremely difficult to translate these approaches into the clinic.